1. Field of the Invention
The present invention is related to a light emitting diode driving integrated circuit with a multi-step current setting function and a method of setting a multi-step current of a light emitting diode driving integrated circuit, and particularly to a light emitting diode driving integrated circuit with a multi-step current setting function and a method of setting a multi-step current of a light emitting diode driving integrated circuit that can utilize a variable resistor circuit and at least one delay unit to change current flowing through a series of light emitting diodes in a plurality of steps.
2. Description of the Prior Art
In the prior art, after a light emitting diode driving integrated circuit utilizes a reference voltage generation circuit to generate a reference voltage, the reference voltage can control a voltage of one terminal of a series of light emitting diodes to regulate the voltage of the terminal of the series of light emitting diodes to a target voltage (such as 0.6V) through a closed loop formed by a boost controller.
But, the prior art switches a large current mode of the series of light emitting diodes to a small current mode of the series of light emitting diodes in one step. That is to say, a buffer mechanism does not exist between the large current mode and the small current mode of the series of light emitting diodes. Therefore, when the prior art switches the large current mode of the series of light emitting diodes to the small current mode of the series of light emitting diodes, the target voltage is changed violently because variation of current flowing through the series of light emitting diodes is too large. Thus, a protection function of the light emitting diode driving integrated circuit may fail, the driving integrated circuit may be damaged, or other abnormal operation problems may occur due to the violent variation of the target voltage.